Push/Pull Wire Anchor

ABSTRACT

A method for making a deflectable catheter includes positioning a flexible element along a catheter liner. A flexible element distal portion extends along at least a portion of a deflectable distal end portion of the catheter liner. At least one anchor is engaged to the flexible element distal portion. The flexible element resides radially between the catheter liner and a band extending at least part way around a perimeter of the liner. An encapsulant, positioned around at least the flexible element distal portion, forms at least a portion of a sidewall of the deflectable distal end portion of the liner. The anchor and band are within the sidewall so that the encapsulant transmits pushing and pulling forces from the at least one anchor to the deflectable distal end portion of the liner.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.11/149,079, filed on Jun. 9, 2005, which is incorporated herein byreference.

TECHNICAL FIELD

A push-pull wire anchor and in particular a push-pull wire anchor in adeflectable catheter for transmitting pushing and pulling forces withoutfailure of the catheter.

BACKGROUND

It is often difficult to provide reliable couplings between a push-pullwire and the deflectable distal end portion of a deflectable catheter.Welding or soldering the push-pull wire to a marker band in thedeflectable distal end portion can anneal a portion of the wire adjacentto the weld. The annealed portion of the wire is sometimes weakenedrelative to the rest of the push-pull wire. When the push-pull wireexperiences the stress of repeated pushing and pulling from an actuatorthe wire may fracture in the annealed region. Additionally, the markerband extends remotely from the push-pull wire around the catheter body.Pushing and pulling forces can tear the pull ring apart through shearingforces thereby freeing the push-pull wire to undesirably move within thecatheter.

Often, the deflectable distal end portion of the catheter is in adeflected position within a curved vessel when the push-pull wirefractures. If pushing forces are applied to the push-pull wire afterfracture, the fractured end of the push-pull wire may puncture thesidewall of the deflected catheter. Further, if the catheter is in asubstantially non-deflected position and pushing forces are applied todeflect the catheter, the fractured end of the push-pull wire maypuncture the distal end of the catheter.

Moreover, fracturing the wire prevents transmission of pushing andpulling forces to the deflectable distal end portion. Failure of thepush-pull wire can complicate a medical procedure. For instance, thecatheter must be withdrawn through curving vasculature, possibly in adeflected position created prior to fracture of the push-pull wire. Thedeflected catheter can snag within the vasculature and complicate theextraction. Further, the catheter must be exchanged with anotherdeflectable catheter and the vasculature traversed again to complete themedical procedure.

In other examples, the push-pull wire is retained within a deflectabledistal end portion by adhesives and the like. Assembling a catheter withan adhered push-pull wire is complex and requires hollowing out aportion of the catheter and injecting the adhesive into the hollowed outportion of the catheter to couple the push-pull wire with thedeflectable distal end portion. In still other examples, the push-pullwire is adhered to the catheter with a hardened distal end portion. Thepush-pull wire is potted (i.e., covered on its distal and side surfaces)with the adhesive that forms the distal end portion. Compressivestresses from the push-pull wire can dislodge the distal end portion andcause failure of the catheter. Additionally, the adhesives used to formthe distal end portion create a hard structure that has little or nodeformability and can therefore be traumatic when engaged against thesoft tissues of vasculature and organs.

What is needed is a push-pull wire anchor that overcomes theshortcomings of previous designs. What is further needed is a push-pullwire anchor that substantially prevents fracture of the push-pull wireand puncturing of a catheter by a fractured push-pull wire.

SUMMARY

A deflectable catheter for a catheter assembly includes a catheter bodyincluding a deflectable distal end portion. A flexible element (e.g., apush-pull wire) including a flexible element distal portion extendsalong at least a portion of the deflectable distal end portion. At leastone anchor, such as a skirt extends at least part way around theflexible element distal portion and is coupled with the flexibleelement. In one option, the skirt is integral to the flexible elementdistal portion. An encapsulant is coupled between the skirt and thedeflectable distal end portion. The encapsulant is adapted to transmitpushing and pulling forces from the skirt to the deflectable distal endportion, and the encapsulant forms at least a portion of an outersurface of the deflectable distal end portion. The tension strength andcompression strength of the flexible element and the at least one skirtare at least as strong as the encapsulant tension strength andcompression strength. The skirt includes at least one recess (e.g.,holes, corrugations, grooves or the like) dimensioned and configured toreceive the encapsulant, in yet another option.

Several options for the deflectable catheter follow. In one option, atleast one weld couples the flexible element distal portion to thedeflectable distal end portion, and the at least one weld is distal tothe at least one skirt. In another option, the at least one skirtincludes a flared portion.

The flared portion includes at least one recess (e.g., hole, corrugationor the like) optionally.The at least one skirt includes, in yet another option, a clampsubstantially surrounding the flexible element distal portion. The clampis crimped at a plurality of points along the clamp, optionally.

In another option, at least one of the skirt and the flexible elementdistal portion include at least one projection. At least one of theskirt and the distal portion include at least one recess sized andshaped to receive the at least one projection, optionally. In yetanother option, the at least one projection extends from the skirt andengages against the flexible element distal portion substantiallyimmobilizing the at least one skirt relative to the flexible element. Instill another option, the skirt includes knurling, brazing dots or thelike.

A method for making a deflectable catheter includes positioning aflexible element along a catheter liner. A distal portion of theflexible element extends along at least a portion of a deflectabledistal end portion of the catheter liner. At least one skirt is coupledto the distal portion, and the at least one skirt extends at least partway around the flexible element distal portion. The method furtherincludes positioning an encapsulant around at least the flexible elementdistal portion and the deflectable distal end portion. The encapsulantis squeezed around the flexible element distal portion and the skirt,and the encapsulant forms at least a portion of a sidewall of thedeflectable distal end portion and at least the skirt is within thesidewall. The encapsulant is adapted to transmit pushing and pullingforces from the at least one skirt to the deflectable distal endportion. The tension strength and compression strength of the flexibleelement and the at least one skirt are at least as strong as theencapsulant tension strength and compression strength.

Several options for the method follow. In one option, the methodincludes substantially preventing a puncture of the encapsulant by theflexible element (e.g., the encapsulant grasps the skirt and the skirtis coupled to the flexible element). In another option, a marker band iscoupled substantially adjacent to the deflectable distal end portion.The marker band is distal relative to the skirt. The flexible elementdistal portion is welded to the marker band. The method includes, in yetanother option, substantially preventing fracture of the flexibleelement adjacent to the marker band.

In another option, the skirt includes a clamp, and the clamp is deformedto grasp the flexible element distal portion. The clamp is crimped at aplurality of points along the clamp, optionally. The method includes, inyet another option, engaging a projection extending from at least one ofthe skirt and the flexible element distal portion against the other ofthe skirt and the distal portion. In still another option, engaging theprojection includes seating the projection within at least one recesssized and shaped to receive the projection, wherein the recess is formedin at least one of the skirt and the flexible element distal portion.Optionally, the method includes deforming at least one of the flexibleelement and the skirt with the projection to form the recess.

The above described catheter allows for deflection of a deflectabledistal end portion while substantially preventing fracture of a flexibleelement. Pushing and pulling forces from the flexible element aretransmitted through the skirt to the encapsulant and the catheter linerat the deflectable distal end portion of the catheter. The skirtanchored in the encapsulant facilitates deflection of the deflectabledistal end portion through transmission of the pushing and pullingforces. In one option, the skirt is integral to the flexible elementdistal portion. Where the flexible element distal portion is not coupledto a marker band optionally, the skirt and the flexible element aredisposed along the catheter body proximal to a marker band used to seethe tip of the catheter body during procedures (e.g., with fluoroscopy).Proximally positioning the skirt provides additional space to includefeatures, for instance flush openings and the like, positioned betweenthe skirt and marker band.

The flexible element and the skirt have tension and compressionstrengths at least as great as the tension and compression strengths ofthe encapsulant to substantially reduce fracture of the flexibleelement. Optionally, the catheter body is adapted to fail before failureof the flexible element and the skirt, and puncturing of the catheterbody is thereby substantially prevented by a fractured element. Inanother option, the skirt is coupled to the flexible element distalportion without a weld. Fracturing of the flexible element is therebysubstantially reduced because stress is not applied to a weakenedannealed region. Additionally, the skirt is localized around theflexible element without extending remotely around the deflectabledistal end portion. The skirt thus provides improved strength anddurability against failure through shearing. Moreover, because the skirtis localized substantially adjacent to the flexible element pushing andpulling forces are not distributed around the catheter body. Thedeflectable distal end portion thus experiences an improved deflectionresponse with the concentrated pushing and pulling of the flexibleelement.

In another option, the skirt cooperates with the marker band coupled tothe flexible element distal portion. The marker band is coupled to theflexible element distally relative to the skirt. The skirt acts as asupplementary anchor and distributes pushing and pulling forces betweenthe marker band and itself. Fracturing of the flexible element adjacentto the marker band (e.g., the annealed region near a weld) issubstantially reduced because the pushing and pulling forces aredistributed between the skirt and the marker band. Additionally, wherethe flexible element distal portion does fracture adjacent the markerband, the skirt embedded in the encapsulant acts to substantiallyimmobilize the fractured flexible element and substantially preventpuncturing of the catheter body. Moreover, the skirt facilitatescontinued use of the catheter with a fractured flexible element becausethe skirt continues to function as an anchor and transmits pushing andpulling forces to the deflectable distal end portion.

Additionally, the encapsulant is squeezed around the catheter liner toeasily form an outer surface and sidewall of the catheter body and graspthe skirt. In one option, the skirt is in the sidewall and therebyprovides a larger moment to the deflectable distal end portion becauseit is positioned remotely from the center of the catheter body. Asdescribed above, the encapsulant flows around the skirt and, whenhardened, transmits tension and compression forces to the deflectabledistal end portion while also acting as the outer surface of thecatheter body. Complex manufacturing procedures including drillingand/or forming a pocket for an anchor and injecting an adhesive over theanchor are thereby avoided. Further, the skirt is retained along thecatheter body and the distal end therefore does not house the skirtand/or the flexible element in a hard tip. In one option, the distal endof the catheter body thereby has a soft atraumatic tip.

These and other embodiments, aspects, advantages, and features of thepresent invention will be set forth in part in the description whichfollows, and in part will become apparent to those skilled in the art byreference to the following description of the invention and referenceddrawings or by practice of the invention. The aspects, advantages, andfeatures of the invention are realized and attained by means of theinstrumentalities, procedures, and combinations particularly pointed outin the appended claims and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of one example of a catheter in a firstdeflected position.

FIG. 1B is a perspective view of the catheter in a non-deflectedposition.

FIG. 1C is a perspective view of the catheter in a second deflectedposition.

FIG. 2 is a perspective view of one example of the deflectable distalend portion.

FIG. 3 is a cross-sectional view of one example of a catheter assembly.

FIG. 4A is a partial sectional view of another example of a catheterassembly.

FIG. 4B is a partial sectional view of another example of a catheterassembly.

FIG. 4C is a perspective view of one example of an anchor.

FIG. 4D is a partial sectional view of another example of a catheterassembly.

FIG. 5A is a perspective view of another example of an anchor.

FIG. 5B is a perspective view of yet another example of an anchor.

FIG. 6 is a cross-sectional view of yet another example of a catheterassembly.

FIG. 7 is a cross-sectional view of still another example of a catheterassembly.

FIG. 8A is a perspective view of one example of a catheter assembly.

FIG. 8B is a perspective view of one example of an anchor.

FIG. 8C is a perspective view of another example of an anchor.

FIG. 8D is a perspective view of yet another example of an anchor.

FIG. 9 is a cross-sectional view of one example of a catheter assembly.

FIG. 10 is a cross-sectional view of another example of a catheterassembly.

FIG. 11 is a partial sectional view of another example of thedeflectable distal end portion.

FIG. 12 is a block diagram illustrating one example of a method formaking a catheter assembly.

DESCRIPTION OF THE EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which is shown byway of illustration specific embodiments in which the invention may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized and that structuralchanges may be made without departing from the scope of the presentinvention. Therefore, the following detailed description is not to betaken in a limiting sense, and the scope of the present invention isdefined by the appended claims and their equivalents.

FIGS. 1A, B, C illustrate a deflectable catheter assembly 100, whereFIG. 1A illustrates the deflectable catheter assembly 100 in onearticulated position, and FIG. 1C illustrates the catheter assembly inanother articulated orientation. FIG. 1B illustrates the deflectablecatheter assembly 100 in an unarticulated position. The deflectablecatheter assembly 100 includes a catheter body 110 and a handle assembly150 that houses actuating mechanisms for deflecting the catheter body110. The handle assembly 150 allows for the selectable deflection of adeflectable distal end portion 102 of the catheter body 110 into anynumber of disparate orientations. One example of the handle assembly 150is described in co-pending application Ser. No. 10/179,633, assigned toEnpath Medical, Inc., entitled ARTICULATING HANDLE FOR A DEFLECTABLECATHETER, which is incorporated herein by reference. As shown in FIGS.1A, B, C the actuating mechanism includes a wheel 104. The wheel 104 isrotated to deflect the deflectable distal end portion 102 into theorientations shown in FIGS. 1A, C. In another option, the handleassembly 150 includes a slide, knob, pull ring or the like to facilitatedeflection of the deflectable distal end portion 102.

As shown in FIGS. 2-10, the catheter body 110 includes a flexibleelement 200, for instance a push-pull wire or the like. Optionally, theflexible element 200 is constructed with, but is not limited to steel,polymers or the like. The flexible element 200 is coupled between theactuating mechanisms in the handle assembly 150 (FIG. 1) and thedeflectable distal end portion 102. As shown in FIGS. 1A, C, whentension or compression is applied to the flexible element 200 (e.g.,using the wheel 104), corresponding pushing or pulling forces areexperienced by the deflectable distal end portion 102 causing thedeflectable distal end portion 102 to curve in predetermined directions.The distal end portion 102 is deflected, in one option, to traversevasculature with the catheter assembly 100.

Referring again to FIGS. 1A, B, C, the catheter body 110 includes anelongate tubular construction that is flexible yet substantiallynon-compressible along its length. The deflectable catheter body 110extends from a proximal end 106 to the deflectable distal end portion102. The deflectable distal end portion 102, in one option, is adaptedto be disposed within a patient. As described above, at the proximal end106 the deflection of the deflectable catheter body 110 is controlledwith the handle assembly 150 containing the actuator mechanism coupledto the flexible element 200 (FIG. 2) and the wheel 104. The distal endportion 102 is deflected to traverse various branch vessels with thecatheter assembly 100 (FIGS. 1A and 1C).

FIG. 2 illustrates a partial cut-away of one example of the deflectabledistal end portion 102 of the catheter body 110 shown in FIGS. 1A, B, C.The catheter body 110 includes a catheter liner 202 having a catheterlumen 204 extending therein (e.g., the catheter liner 202 defines thecatheter lumen 204). The catheter lumen 204 is sized and shaped toreceive a variety of instruments, fluids or the like. In one option, thecatheter lumen 204 extends through the catheter body 110 to the handleassembly 150 (FIG. 1). The distal end of the catheter liner 202 forms atleast a portion of the deflectable distal end portion 102. The catheterliner 202 includes, but is not limited to, flexible materials withsufficient strength and wear resistance for use in the catheter assembly100. In one example, the catheter liner 202 includes a polymer such aspolytetrafluoroethylene used under the trademark TEFLON® registered toE.I. Du Pont De Nemours and Company.

A flexible element duct 206 is positioned along the catheter liner 202,in one option. The flexible element duct 206 is substantially parallelto the catheter liner 202 and extends along at least a portion of thecatheter liner 202, in another option. For instance, as shown in FIG. 2,the flexible element duct 206 extends from an intermediate portion 207of the catheter body 110 (e.g., proximal to the deflectable distal endportion 102) toward the proximal end 106 adjacent to the handle assembly150 (FIGS. 1A, B, C). In another example, the distal end 208 of theflexible element duct 206 is proximal to a distal tip 210 of thecatheter body 110. The flexible element duct 206 includes an actuatorlumen sized and shaped to receive the flexible element 200 (e.g., theflexible element duct 206 defines the actuator lumen). In one option,the flexible element 200 is slidably coupled with the flexible elementduct 206 to facilitate transmission of pushing and pulling forces fordeflection of the deflectable distal end portion 102.

In one option, a distal portion 201 of the flexible element 200 extendsfrom the distal end 208 of the flexible element duct 206 toward thedistal tip 210 of the catheter body 110. In another option, the flexibleelement distal portion 201 extends from the distal end 208 of the duct206 toward a marker band 212. The marker band 212 extends around thecatheter liner 202. Optionally, the marker band 212 is coupled to thecatheter liner 202 with crimping, adhesives, overmolding or the like.The marker band 212 is fluoroscopic in still another option,facilitating viewing of the deflectable catheter distal end portion 102during procedures (e.g., when the catheter body 110 is withinvasculature). As shown in one example of the catheter body 110 in FIG.2, the flexible element distal portion 201 is optionally coupled to themarker band 212. The distal portion 201 and the marker band 212 arecoupled together with, but not limited to, welds, adhesives, mechanicalfasteners or the like.

The catheter liner 202, flexible element duct 206, flexible element 200,and the marker band 212 are surrounded by an encapsulant 214. In oneoption, the encapsulant 214 includes a biocompatible metal, polymer andthe like. In one example, the encapsulant 214 includes apoly-ether-block amide compound such as PEBAX® a trademark registered tothe Atofina Corporation. The components of the catheter body 110 areencapsulated with the encapsulant 214, optionally, by heating theencapsulant to a molten state and squeezing it around catheter liner202, flexible element duct 206, flexible element 200 and the marker band212. The encapsulant 214 flows around the components, grasps them, andsolidifies when cooled to form the catheter body 110. The encapsulant214 forms a sidewall 215 and at least a portion of an outer surface 217of the catheter body 110 surrounding the catheter lumen 204. At leastthe flexible element duct 206 and the flexible element 200 are containedwithin the encapsulant 214 and outside of the catheter lumen 204. Theencapsulant 214 forms the outer surface 217 of at least a portion of thedeflectable distal end portion 102, optionally. The encapsulant providesa smooth outer surface 217 and is easily positioned around the catheterbody 110 (e.g., heated and squeezed around the catheter body 110).Complex manufacturing procedures including drilling and/or forming apocket for an anchor and injecting an adhesive over the anchor arethereby avoided.

In another option, the encapsulant 214 is squeezed around the catheterliner 202 and the other components with shrink tubing 216. The shrinktubing 216 contracts when exposed to heat and squeezes the moltenencapsulant 214 around the catheter liner 202 and the other components.The shrink tubing 216 ensures the encapsulant 214 provides a smoothconsistent cross-sectional geometry for the catheter body 110.Optionally, the shrink tubing 216 is constructed with, but not limitedto, polymers, such as Fluoro Ethylene Propylene. In yet another option,the shrink tubing 216 is split and removed from the catheter body 110after the encapsulant 214 has solidified. As shown in FIG. 2, the shrinktubing 216 remains coupled around the encapsulant 214.

Optionally, the catheter body 110 includes a stiffening member embeddedwithin the encapsulant, such as a braided member 218. In one option, thebraided member 218 includes a stainless steel braid. The stiffeningmember facilitates rotation of the deflectable distal end portion 102from the proximal end 106. Additionally the stiffening member alsoassists in preventing the catheter body 110 from collapsing. In anotheroption, the stiffening member extends from the proximal end 106 to thedeflectable distal end portion 102. The stiffening member extends formthe proximal end 106 to the intermediate portion 207 of the catheterbody 110, in yet another option. In this option, at least a portion ofthe deflectable distal end portion 102 is free of the stiffening memberthereby enhancing the deflection capability of the distal end portion102.

FIG. 2 illustrates one example of an anchor, such as a skirt 220disposed around the distal portion 201 of the flexible element 200. Theskirt 220 is a separate feature from the marker band 212. Optionally,the skirt 220 is proximal relative to the marker band 212. The skirt220, in one option, is integral to the flexible element 200. In anotheroption, the skirt 220 is coupled to the flexible element 200, forexample by crimping, disposing projections within recesses, overmoldingor the like. The skirt 220 is thereby substantially immobilized alongthe flexible element 200. In yet another option, the skirt 220 partiallyextends around the flexible element distal portion 201. In one example,the skirt 220 extends around the flexible element distal portion 201approximately 180 degrees. In another example, the skirt 220 extendsfurther (e.g., all the way) or less around the flexible element distalportion 201.

The skirt 220 provides a larger profile along the flexible element 200than the element 200 itself. The profile of the skirt 220 allows theencapsulant 214 to grasp the skirt 220 and thereby easily couple withthe flexible element distal portion 201 to allow transmission of pushingand pulling forces to the deflectable distal end portion 102. The skirt220 anchors the flexible element distal portion 201 within theencapsulant 214. Pushing and pulling forces are thereby transmitted fromthe skirt 220 through the encapsulant 214 and to the catheter liner 202facilitating deflection of the deflectable distal end portion 102. Theencapsulant 214 forms the outer surface 217 of at least a portion of thedeflectable distal end portion 102, optionally. In yet another option,the encapsulant 214 forms the sidewall 215 of the deflectable distal endportion 102 and the skirt 220 is retained within the sidewall 215 andadjacent to the outer surface 217. Positioning the skirt 220 within thesidewall 215 and adjacent to the outer surface 217 allows for anincreased moment to be applied for deflection of the deflectable distalend portion 102 because the skirt 220 and the flexible element distalportion 201 are positioned remotely from the longitudinal center of thecatheter body 110. Additionally, in still another option, the skirt 220is fully encapsulated to further enhance transmission of pushing andpulling forces to the deflectable distal end portion 102. Further, theskirt 220 is retained along the catheter body 110, in an option, therebyallowing the distal tip 210 to have an atraumatic (i.e., deformable)surface for engaging with vasculature and organs.

As shown in FIGS. 4-8, the skirt 220 includes, optionally, additionalfeatures (e.g., knurling, projections, grooves, or the like) to furtherenhance the engagement of the skirt 220 with the encapsulant 214. Instill another option, the skirt 220 is coupled to the catheter liner 202with adhesives, mechanical fasteners, or the like, thereby facilitatingtransmission of pushing and pulling forces to the deflectable distal endportion 102.

In another option, where the catheter body includes the marker band 212,as shown in FIG. 2, the encapsulant grasps the skirt 220, the markerband 212 and the catheter liner 202. The pushing and pulling forces fromthe flexible element 200 are transmitted in part from the skirt 220 tothe encapsulant 214 and the catheter liner 202 to deflect the catheterbody 110. Additionally, pushing and pulling forces are transmitted fromthe flexible element 200 to the marker band 212, and from the markerband 212 to the encapsulant 214 and the catheter liner 202. In thisexample, the skirt 220 acts as a supplementary anchor to the marker band202 and distributes the pushing and pulling forces between the skirt 220and the marker band 212. This decreases the stresses on the couplingbetween the marker band 212 and the flexible element distal portion 201and substantially prevents failure of the flexible element distalportion 201 adjacent to the marker band 212 (e.g., the region of theflexible element that is annealed from a weld or other treatment thatweakens the element). Because the skirt 220 is proximal relative to themarker band 212, the skirt 220 substantially prevents puncturing of thecatheter body 110 with a fractured flexible element 200 that fails nearthe marker band 212 (e.g., where the element 200 is annealed adjacent aweld or other means of coupling between the element 200 and the markerband 212). The skirt 220 transmits pushing forces to the deflectabledistal end portion 102 and substantially prevents longitudinal movementof the fractured flexible element 200 that could otherwise puncture thecatheter body 110 and cause injury to surrounding vasculature.Additionally, the skirt 220 allows for at least limited deflection ofthe catheter body 110 after fracture, facilitating completion of aprocedure or removal of the catheter body 110 from vasculature.Moreover, the skirt 220 provides a profile that is localized around theflexible element 200 to minimize shearing stresses on the skirt 220 andenhance the lifespan of the skirt 220 while facilitating deflection ofthe deflectable distal end portion 102 and immobilization of a fracturedflexible element.

FIG. 3 shows one example of the skirt 220 coupled along the flexibleelement distal portion 201. The skirt 220 is at least partiallysurrounded by the encapsulant 214 and substantially immobilized in theencapsulant 214. Similar to the example shown in FIG. 2, the skirt 220cooperates with the encapsulant 214 to couple the flexible elementdistal portion 201 to the deflectable distal end portion 102. The markerband 212 is encapsulated as well, but not otherwise coupled to theflexible element 200. The skirt 220 is a separate feature from themarker band 212, and relatively proximal to the band 212. Pushing andpulling forces are thereby transmitted through the skirt 220 to theencapsulant 214 to deflect the distal end portion 102 as shown in FIGS.1A, C.

The skirt 220, shown in FIG. 3, is constructed with a deformablematerial, for instance metals, such as steel, aluminum or the like. Inone option, the skirt 220 acts as a clamp and is deformed around theflexible element distal portion 201 by crimping. The skirt 220 includesa crimped portion 300 that engages against the flexible element distalportion 201 and couples the skirt 220 to the distal portion 201.Crimping the skirt 220 to the distal portion 201 substantiallyimmobilizes the skirt 220 relative to the flexible element 200. Crimpingthe skirt 220 around the flexible element distal portion 201substantially reduces the likelihood of fracturing the flexible element200 with pushing and pulling forces. The skirt 220 is not coupled to theflexible element 200 with a weld or other means, and therefore there isno weakened annealed region along the flexible element 200. The strengthof the flexible element 200 (e.g., tensile and compression strengths) isthereby consistently maintained along the length of the flexible element200. The skirt 220 and the flexible element 200 have tension andcompression strengths at least as great as the tension and compressionstrengths of the encapsulant 214 and thereby substantially reducefracture of the flexible element 200. Optionally, the catheter body 110(FIGS. 1A-C and 2) is adapted to fail before failure of the flexibleelement 200 and the skirt 220, thereby substantially preventing punctureof the catheter body 110 by a fractured flexible element 200. In anotheroption, the skirt 220 includes metals, polymers and the like.Optionally, the skirt 220 is coupled to the flexible element distalportion 201 with adhesives, overmolding and the like.

The skirt 220 includes projections 302, for instance non-crimpedsegments of the skirt 220, sized and shaped to extend from the flexibleelement distal portion 201. The projections 302 are securely grasped bythe encapsulant 214 and anchored therein to firmly couple the skirt 220and the flexible element 200 to the deflectable distal end portion 102.In one example, as shown in FIG. 3, the encapsulant 214 fills a spacedefined by the projections 302 to firmly anchor the skirt within theencapsulant. For instance, the projections 302 form a flared conicalgeometry extending away from the crimped portion 300 of the skirt 220that receives the encapsulant therein. Pushing and pulling forces aretransmitted from the flexible element 200 to the skirt 220 and theprojections 302 are securely grasped by the encapsulant 214. The pushingand pulling forces are transmitted from the skirt 220 and theprojections 302 through the encapsulant 214 to the deflectable distalend portion 102. The skirt 220 thereby pushes and pulls the deflectabledistal end portion 102 to deflect the distal end portion 102 as desired.

FIGS. 4A, B, D illustrate examples of skirts 400A, B, D coupled aroundthe flexible element distal portion 201 extending outside the flexibleelement duct 206. In one option, the skirts 400A, B, D are integral tothe flexible element distal portion 201. In another option, the skirts400A, B, C are coupled to the distal portion 201 of the flexible element200 by crimping, adhesives, overmolding or the like. Where the skirts400A, B, D are crimped along the flexible element distal portion 201,the skirts 400A, B, D are crimped in a similar manner as skirt 220 (FIG.2).

The skirt 400A shown in FIG. 4A has an outer surface 402 includingsurface roughening, texturing, features or the like, such as knurling404. The knurling 404 provides additional features for the encapsulant214 to grasp and firmly anchor the skirt 400A to the deflectable distalend portion 102. The knurling 404 assists in substantially immobilizingthe skirt 400A within the encapsulant 214. Pushing and pulling forcesare thereby readily transmitted through the skirt 400A to deflect thedistal end portion 102 through the encapsulant 214. In one option, wherethe flexible element distal portion 201 is welded to the marker band 212(FIG. 2), the knurling 404 enhances the immobilization of the skirt 400Aand assists in substantially preventing a fractured flexible element 200from puncturing the catheter body 110 (FIG. 1).

The knurling 404 is formed along the skirt 400A by molding, crimping, orthe like. In one option, the knurling 404 along the skirt 400A is formedwith a crimping tool having a working surface with correspondingrecesses. When the skirt 400A is crimped with the tool the skirt outersurface 402 assumes a configuration corresponding to the crimping tool(i.e., the knurling 404 is in a pattern corresponding to the recesses).In one option, the knurling 404 is formed on the skirt 400A withoutcrimping the skirt 400A to the flexible element distal portion 201. Inanother option, the skirt 400A is crimped around the distal portion 201after forming the knurling 404. The skirt 400A is adhered, overmolded orthe like to couple the skirt 400A to the distal portion 201, in yetanother option. The knurling 404 is formed on the skirt 400A and theskirt is crimped around the distal portion 201 in one step, optionally.

FIG. 4B illustrates a skirt 400B similar in some respects the skirt 400Ashown in FIG. 4A. Skirt 400B includes ridges 406 formed along the outersurface 402 of the skirt 400B. As with the knurling 404 (FIG. 4A), theridges 406 provide additional features for the encapsulant 214 to graspand firmly anchor the skirt 400B to the deflectable distal end portion102. Optionally, where the flexible element 200 is welded to the markerband 212, the ridges 406 enhance the immobilization of the skirt 400Band assist in substantially preventing a fractured flexible element frompuncturing the catheter body 110 (See FIG. 2). In one option, the ridges406 are formed along the skirt 400B by molding, crimping, or the like.In another option, the skirt 400B is crimped adhered, overmolded or thelike to couple the skirt 400B to the flexible element 200.

FIG. 4C illustrates a skirt 400C including recesses, for instance,corrugations 410. The corrugations 410 provide features for theencapsulant 214 (FIG. 2) to flow into and enhance the grasp of theencapsulant on the skirt 400C. The encapsulant 214 and the skirt 400Ccooperate to anchor the flexible element distal portion 201 (FIG. 2) inthe deflectable distal end portion 102 (FIG. 2). The skirt 400C, in oneoption, has an annular shape as shown in FIG. 4C and the corrugations410 extend around the annular perimeter of the skirt 400C. Thecorrugations 410 facilitate transmission of pushing and pulling forcesthrough the skirt 400C to the encapsulant 214 to deflect the distal endportion 102.

The skirt 400C is stamped, in one option, to create the corrugations410. In another option, the skirt 400C is formed with the corrugations410 prior to crimping the skirt 400C to the flexible element distalportion 201 (FIG. 2). The skirt 400C includes a flexible element lumen412. In one option, the flexible element distal portion 201 is insertedinto a non-corrugated portion 412 of the skirt 400C and thenon-corrugated portion 412 is crimped to couple the skirt 400C with thedistal portion 201. In another option, the flexible element distalportion 201 is inserted into the flexible element lumen 412 and theskirt 400C is stamped to form the corrugations 410 and couple the skirt400C to the flexible element distal portion 201. In yet another option,the flexible element distal portion 201 extends through the skirt 400Cand is welded to the marker band 212 (FIG. 2). The corrugations 410increase the immobilization of the skirt 400C and substantially preventfracturing of the flexible element 200 (FIG. 2). The skirt 400C preventsa fractured flexible element 200 from puncturing the catheter body 110.

FIG. 4D illustrates a skirt 400D. The outer surface 402 of the skirt400D includes recesses 408. The recesses 408 provide additional featuresfor the encapsulant 214 to flow into and firmly anchor the skirt 400D tothe deflectable distal end portion 102. The recesses 408 thereby enhancetransmission of pushing and pulling forces through the skirt 400D todeflect the distal end portion 102. Additionally, where the flexibleelement distal portion 201 is welded to the marker band 212 (FIG. 2) inone option, the recesses 408 increase the immobilization of the skirt400D and substantially prevent a fractured flexible element frompuncturing the catheter body 110 (FIG. 2). Optionally, the recesses 408include openings extending through the skirt 400D.

The recesses 408 are formed along the skirt 400D by molding, crimping,stamping, drilling, etching, or the like. In one option, the recesses408 along the skirt 400D are formed with a crimping tool having aworking surface with bosses corresponding to the pattern of the recesses408. When the skirt 400D is crimped with the tool the skirt outersurface 402 assumes a configuration corresponding to the crimping tool(i.e., the recesses 408 are in a pattern corresponding to the bosses).As described above for the skirt 400A, optionally, the skirt 400D iscrimped to form the recesses 408 and couple the skirt 400D to theflexible element distal portion 201. In another option, the skirt 400Dis crimped to form the recesses 408 and crimped again to couple theskirt 400D to the flexible element 200. In yet another option, the skirt400D is adhered, overmolded or the like to couple the skirt 400D to theflexible element 200.

FIGS. 5A, B show examples of skirts 500A, B including recesses 502dimensioned and configured to receive encapsulant 214 (FIG. 2).Referring now to FIG. 5A, during forming of the deflectable distal endportion 102 (FIG. 1) the encapsulant 214 flows into the recesses 502 andimmobilizes the skirt 500A within the encapsulant 214. The recesses 502allow the encapsulant 214 to grasp the skirt 500A and facilitatetransmission of pushing and pulling forces to the deflectable distal endportion 102. In one option, the recesses 502 are formed by drillingholes in a pattern along a portion of the skirt 500A. Optionally, therecesses 502 are formed by stamping, etching or the like. As shown inFIG. 5B, additional recesses 502 are formed in the skirt 500B. Thelarger number of recesses 502 allow for additional penetration of theencapsulant 214 (FIG. 2) and enhance the immobilization of the skirt500B.

The skirt 500A is coupled to the flexible element distal portion 201(FIG. 2) by inserting the flexible element distal portion 201 at leastpartially through a flexible element lumen 506. In one option, a portion504 of the skirt 500A, which does not have recesses, is crimped aroundthe flexible element distal portion 201. Crimping the portion 504provides a strong coupling between the skirt 500A and the flexibleelement distal portion 201. In another option, the entire skirt 500A iscrimped around the flexible element distal portion 201. The skirt 500Ais coupled with the flexible element distal portion 201 so the portion504 is proximal relative to the recesses 502 and the distal tip 210 ofthe catheter body 110 (FIG. 1), optionally. In still another option, theskirt 500A is coupled so the recesses 502 are proximal relative to thedistal tip 210 and the non-recessed portion 504. The skirt 500B, shownin FIG. 5B, is coupled to the flexible element distal portion 201 in asimilar manner as described above. The skirts 500A, B are constructedwith, but not limited to metals, in one option. For instance, the skirts500A, B include stainless steel.

FIG. 6 shows another example of a skirt 600 embedded within theencapsulant 214. In the example shown in FIG. 6, the deflectable distalend portion 102 includes the distal portion 201 of the flexible element200 extending from the flexible element duct 206. The skirt 600 iscoupled along the flexible element distal portion 201. As shown, theflexible element distal portion 201 is not coupled with the marker band212. In another option, the distal portion 201 is coupled to the markerband 212 (FIG. 2), for instance, with a weld.

The skirt 600 acts as a clamp and is deformable. In one option, theskirt 600 includes, but is not limited to, metals such as steel,aluminum or the like. In another option, the skirt 600 extends part wayaround the distal portion 201 of the flexible element 200. The skirt 600extends fully around the distal portion 201, in yet another option.Prior to coupling the skirt 600 with the flexible element distal portion201, the skirt 600 has an inner surface 602 sized and shaped to fitaround the flexible element 200 and allow positioning of the skirt 600along the element 200. Optionally, the inner surface 602 has asubstantially cylindrical geometry prior to coupling of the skirt 600 tothe flexible element 200.

In one option, the skirt 600 is positioned along the flexible elementdistal portion 201 and deformed (e.g., crimped) to engage against thedistal portion 201. The skirt 600 is thereby substantially immobilizedalong the flexible element 200. As shown in FIG. 6, the skirt 600 isdeformed at a discrete point to create at least one projection, such asspur 604. In the example shown in FIG. 6, the skirt 600 is deformed toinclude four spurs 604. The spurs 604 engage the inner surface 602 ofthe skirt 600 with the flexible element distal portion 201. Optionally,the flexible element distal portion 201 includes projections and theinner surface 602 of the skirt 600 is crimped over the projections tocouple the skirt to the distal portion 201.

In another option, the spurs 604 extend into the flexible element 200and deform the flexible element 600 to define corresponding recessessized and shaped to receive the spurs 604. Optionally, the spurs 604extend between individual filars of the flexible element 200 (e.g., awire with a plurality of steel filars). The spurs 604 immobilize theskirt 600 along the flexible element 200 without substantially weakeningthe flexible element 200. Additionally, the spurs 604 allow the skirt600 to have a substantially enlarged uncrimped profile while only asmall portion of the skirt 600 is narrowed to form the spurs 600. Whencoupled to the flexible element 200 with the spurs 604, the skirt 600has a larger profile and improved anchoring within the encapsulant 214.In another option, the skirt 600 includes additional features, such asknurling, ridges, recesses or the like, as previously described. Theseadditional features provide an even larger profile for the encapsulant214 to grasp and anchor the skirt 600, further enhancing transmission ofpushing and pulling to the deflectable distal end portion 102. Inanother option, where the flexible element distal portion 201 is coupledto a marker band 212 (FIG. 2), the skirt 600 substantially preventspuncturing of the catheter body 110 if the flexible element 200fractures adjacent to the marker band 212.

FIG. 7 shows yet another example of a skirt 700 coupled along the distalportion 201 of the flexible element 200. In one option, the flexibleelement distal portion 201 is free of welds and is not coupled with themarker band 212. In another option, the flexible element distal portion201 is coupled to the marker band 212 (See FIG. 2) distally relative tothe skirt 700. The distal portion 201 is optionally welded to the markerband 212.

In one option, the skirt 700 acts as a clamp and is deformable to engageagainst the flexible element distal portion 201. As described above, theskirt 700 includes, but is not limited to, metals such as steel,aluminum or the like. In another option, the skirt 700 is overmoldedaround the flexible element distal portion 201 to couple the skirt 700to the flexible element 200. The skirt 700 includes, for instance, butis not limited to metals, polymers or the like. Optionally, the skirt700 extends part way around the flexible element distal portion 201. Theskirt 700 extends fully around the distal portion 201, in anotheroption.

As shown in FIG. 7, the skirt 700 includes projections 702 sized andshaped to fit within recesses 704 formed in the flexible element distalportion 201. In one option, the ends of the skirt 700 are crimped toform the projections 702. The projections 702 engage the distal portion201 and form the recesses 704. In another option, the recesses 704 arepre-formed in the flexible element distal portion 201 and theprojections 702 are positioned within the recesses 704 to engage theskirt 700 to the distal portion 201. The recesses are formed,optionally, by deformation of the flexible element, etching, drilling orthe like. In yet another option, the skirt 700 includes recesses and theflexible element distal portion 201 includes projections sized andshaped to fit within the recesses.

When coupled to the flexible element distal portion 201, the skirt 700is substantially immobilized along the flexible element 200. The skirt700 provides an enlarged profile for the flexible element distal portion201 and facilitates grasping of the flexible element 200 by theencapsulant 214. Optionally, the skirt 700 includes additional features,such as knurling, ridges, recess or the like, as described above.Additional features present an even larger profile for the encapsulant214 to anchor the skirt 700, further enhancing transmission of pushingand pulling to the deflectable distal end portion 102 through theencapsulant 214. In another option, where the flexible element distalportion 201 is coupled to a marker band 212 (FIG. 2), the skirt 700substantially prevents puncturing of the catheter body 110 if theflexible element 200 fractures adjacent to the marker band 212.

FIG. 8A shows one example of the deflectable distal end portion 102including a skirt 800A having a flared portion 802A (e.g., a paddlegeometry). FIGS. 8B, C, D show additional examples of skirts 800B, C, Dwith flared portions 802B, C, D having different geometries. Each of theflared portions 802A-D provide a large profile for the encapsulant 214(FIG. 8A) to grasp and immobilize the skirts 800A-D. The skirts 800A-Dprovide improved transmission of pushing and pulling forces to thedeflectable distal end portion 102. In another option, where theflexible element distal portion 201 is coupled to a marker band 212(FIG. 2), the skirts 800A-D substantially immobilize the flexibleelement distal portion 201 to prevent puncturing of the catheter body110 if the flexible element 200 fractures adjacent to the marker band212. Optionally, the flared portions 802A-D are located distallyrelative to the flexible element distal portion 201. In another option,the flared portions 802A-D are coincident with the flexible elementdistal portion 201, for instance the tip of the distal portion isdisposed within one of the flared portions 802A-D.

As shown in FIG. 8A, the skirt 800A includes a flared portion 802A and aproximal portion 804. The flared portion 802A provides a wide and flatprofile extending outside of the profile of the proximal portion 804 tofacilitate grasping by the encapsulant 214. The flared portion 802A isformed, in one option, by stamping the skirt 800A in the region distalto the proximal portion 804. In another option, the flared portion 802Ais formed by molding, machining or the like. The skirt 800A isoptionally stamped with a die that defines the geometry of the flaredportion 802A. Other examples of flared portions are shown in FIGS. 8B,C, D. The flared portion 802B (FIG. 8B), in one option, is formed with adie that projects the flared portion 802B away from the proximal portion804 with a curved geometry. In another option, the curved geometrycomplements the rounded geometry of the deflectable distal end portion102. As shown in FIG. 8C, in yet another option, the skirt 800C isstamped with a die that projects the flared portion 802C further awayfrom the proximal portion 804 than the flared portion 802B of skirt800B. The flared portions 802B, C remain substantially adjacent to theproximal portion 804 to substantially minimize shearing of the flaredportions 802B, C. Optionally, the skirts 800A-D are constructed with,but not limited to, deformable materials such as metals that maintainthe geometries of the flared portions 802A-D. In one example, the skirts800A-D include stainless steel.

In another option shown in FIG. 8D, the flared portion 802D is formedwith a die that projects the flared portion 802D away from the proximalportion 804 and also forms at least one recess, such as corrugation 806.The corrugation 806 defines a non-annular feature for the flared portion802D. The profile of the flared portion 802D including the added featureof the corrugation 806 enhances immobilization of the skirt 800D withinthe encapsulant (FIG. 8A). The flared portion 802D having thecorrugation 806 transmits pushing and pulling forces to the deflectabledistal end portion 102 (FIG. 8A).

Referring again to FIG. 8A, the proximal portion 804, in one option,extends substantially around the flexible element distal portion 201 andis crimped around the distal portion 201 to couple the skirt 800A withthe flexible element 200. In another option, the proximal portion 804extends part way around the flexible element distal portion 201 and iscrimped to couple the skirt 800A with the flexible element 200. In asimilar manner, the proximal portions 804 of the skirts 800B, C, D arecrimped to couple the skirts with the flexible element 200, optionally.In yet another option, the skirts 800A-D are coupled with the flexibleelement with other means including, but not limited to, adhesives,molding or the like.

A deflectable distal end portion 102 including a skirt 900 integral tothe flexible element distal portion 201 is shown in FIG. 9. The skirt900 includes features, such as knurling 902, provided to anchor theflexible element distal portion 201 within the encapsulant 214. In oneoption, the knurling 902 extends around the distal portion 201. Inanother option, the knurling 902 extends part way around the distalportion 201.

Optionally, the knurling 902 includes brazing dots formed with metalssuch as aluminum, copper and the like. The brazing dots are applied tothe flexible element distal portion 201 by melting the brazing materialand applying it as dots. The brazing dots cool and solidify to form theknurling 902. In another option, the flexible element 200 is molded,crimped or the like to form the knurling 902. Crimping the flexibleelement 200 compresses the element in one dimension while widening theelement 200 in another dimension.

In a similar manner to the skirts 220, 400A-D, 500A, B, 600, 700 and800A-D, the skirt 900 provides an enlarged profile for the flexibleelement distal portion 201 and facilitates grasping of the flexibleelement 200 by the encapsulant 214. The skirt 900 provides improvedtransmission of pushing and pulling forces to the deflectable distal endportion 102 through the encapsulant 214. In another option, where theflexible element distal portion 201 is coupled to a marker band 212(FIG. 2), the skirt 900 substantially prevents puncturing of thecatheter body 110 if the flexible element 200 fractures adjacent to themarker band 212.

FIG. 10 illustrates another example of a deflectable distal end portion102 including a skirt 1000 integral to the flexible element distalportion 201. The skirt 1000 includes features, such as recesses 1002,provided to receive the encapsulant 214 and thereby anchor the flexibleelement distal portion 201 within the encapsulant 214. In one option,the skirt 1000 further includes flaring 1004 disposed between therecesses 1002 to improve the anchoring of the skirt 1000 within theencapsulant 214. Optionally, the recesses 1002 and/or flaring 1004extend part way around the distal portion 201. The recesses 1002 and/orflaring 1004 extend all the way around the flexible element distalportion 201, in another option.

The recesses 1002 and flaring 1004 are formed, in one option, bycrimping and deforming the flexible element distal portion 201. Therecesses 1002 are formed by crimping, molding, etching or the like alongthe flexible element 200. The flaring 1004 is formed, in another option,by pulling the flexible element distal portion 201 radially to increasethe circumference around the distal portion 201. Where the flexibleelement 200 includes multiple filars (e.g., steel filars), radiallypulling on the element 200 pulls at least some of the filars outward toform the flaring 1004. Optionally, the flaring 1004 is formed as theflexible element 200 is longitudinally compressed along a portion of itslength corresponding to the skirt 1000. The compression bows out thefilars of the flexible element 200 to form the flaring 1004. In yetanother option, the flaring 1004 and/or recesses 1002 are formed alonewithout the other of the flaring 1004 or the recesses 1002.

Similar to the examples described above, the skirt 1000 provides anenlarged profile for the flexible element distal portion 201 andfacilitates grasping of the flexible element 200 by the encapsulant 214.The flaring 1004 and the recesses 1002 anchor the flexible elementdistal portion 201 within the encapsulant 214 to provide improvedtransmission of pushing and pulling forces to the deflectable distal endportion 102. In another option, where the flexible element distalportion 201 is coupled to a marker band 212 (FIG. 2), the skirt 1000substantially prevents longitudinal movement of the flexible elementdistal portion 201 within the catheter body 110, for instance, if theflexible element 200 fractures adjacent to the marker band 212.Puncturing of the catheter body 110 is thereby substantially preventedby anchoring the skirt 1000 within the encapsulant of the deflectabledistal end portion 102.

FIG. 11 shows a partial cut-away of another example of a deflectabledistal end portion 1100 of the catheter body 110 shown in FIGS. 1A, B,C. The deflectable distal end portion 1100 is similar in some respectsto the deflectable distal end portion 102 shown in FIG. 2. The catheterbody 110 includes a catheter liner 202 having a catheter lumen 204extending therein. The distal end of the catheter liner 202 forms atleast a portion of the deflectable distal end portion 1100. A flexibleelement duct 206 is positioned along the catheter liner 202, in oneoption. As shown in FIG. 11, the flexible element duct 206 extends froman intermediate portion 207 of the catheter body 110 (e.g., proximal tothe deflectable distal end portion 102) toward the proximal end 106adjacent to the handle assembly 150 (FIGS. 1A, B, C). In anotherexample, the distal end 208 of the flexible element duct 206 is proximalto a distal tip 210 of the catheter body 110. The flexible element duct206 includes an actuator lumen sized and shaped to receive the flexibleelement 200 (e.g., the flexible element duct 206 defines the actuatorlumen). In one option, the flexible element 200 is slidably coupled withthe flexible element duct 206 to facilitate transmission of pushing andpulling forces for deflection of the deflectable distal end portion 102.

In one option, a distal portion 201 of the flexible element 200 extendsfrom the distal end 208 of the flexible element duct 206 toward thedistal tip 210 of the catheter body 110. In another option, the flexibleelement distal portion 201 extends from the distal end 208 of the duct206 toward a marker band 212. The marker band 212 extends around thecatheter liner 202. Optionally, the marker band 212 is coupled to thecatheter liner 202 with crimping, adhesives, overmolding or the like.The marker band 212 is fluoroscopic in still another option,facilitating viewing of the deflectable distal end portion 1100 duringprocedures (e.g., when the catheter body 110 is within vasculature).

As described above, the catheter liner 202, flexible element duct 206,flexible element 200, and the marker band 212 are surrounded by theencapsulant 214. The encapsulant 214 grasps the components andimmobilizes them with respect to the catheter body 110. The encapsulant214 forms the sidewall 215 and at least a portion of the outer surface217 of the catheter body 110 surrounding the catheter lumen 204. Atleast the flexible element duct 206 and the flexible element 200 arecontained within the encapsulant 214 and outside of the catheter lumen204.

As shown in FIG. 11, the skirt 220 is disposed around the distal portion201 of the flexible element 200. The skirt 220 is grasped by theencapsulant 214 to transmit pushing and pulling forces from the flexibleelement 200 to the deflectable distal end portion 1100 (describedabove). The skirt 220 is a separate feature from the marker band 212.The skirt 220, as shown in FIG. 11, is proximal to the marker band 212and separated from the marker band 212 by a space, such as gap 1102.Because the flexible element distal portion 201 is not coupled with themarker band 212 the skirt 220 and the distal portion 201 are spaced apredetermined distance from the marker band 212. The gap 1102, in oneoption, thereby contains features sandwiched between the skirt 220 andthe marker band 212. The features include, but are not limited to,instruments (e.g., for measuring temperature, pressure and the like),electrodes, openings, such as flush openings 1104 and the like. Theflush openings 1104 are adapted to discharge fluid, including, but notlimited to, saline, contrast media and the like. The flush openings 1104help to prevent blood clots that form around the catheter body 110,clear out air before procedures and inject contrast media (e.g., forfluoroscopy). Because the gap 1102 is variable, combinations of featuresare located in the gap 1102, in another option.

Referring to FIGS. 1A, B, C, in operation, the actuator of the handleassembly 150 (e.g., the wheel 104, slide, knob, pull ring and the like)is moved to deflect the deflectable distal end portion 102 from aneutral position (FIG. 1B) to disparate deflected orientations, such asthe orientations shown in FIGS. 1A, C. Referring now to FIG. 2, theflexible element 200 is pushed and/or pulled by the actuating mechanismsin the handle assembly 150 to deflect the distal end portion 102. Thepushing and pulling forces are transmitted along the flexible element200 to the flexible element distal portion 201. The distal portion 201,in one option, is coupled to the deflectable distal end portion 102 atthe marker band 212 and by encapsulating the skirt 220 within theencapsulant 214. The pushing and pulling forces are transmitted to thecatheter liner 202 and the encapsulant 214 by the skirt 220 and themarker band 212. The pushing and pulling forces transmitted by themarker band 212 and the skirt 220 deflect the deflectable distal endportion 102 into a desired orientation (e.g., the orientations shown inFIGS. 1A, C). Optionally, skirts 400A-D, 500A, B, 600, 700 and 800A-D,900 and 1000 are used in a similar manner during operation of thecatheter assembly 100. In another option, multiple skirts are used alongthe flexible element distal portion 201.

The skirt 220 operates to distribute the pushing and pulling stressesaway from the marker band 212 and thereby substantially reducefracturing of the flexible element distal portion 201 adjacent to themarker band 212, for instance at an annealed region near a weld.Additionally, the skirt 220 and the flexible element 200 have tensionand compression strengths equal to or greater than the correspondingtension and compression strengths of the encapsulant 214. Fracture ofthe flexible element 200 is thereby substantially reduced and thecatheter body 110 (FIGS. 1A-C and 2) is adapted to fail before failureof the element 200 and the skirt 220, thereby substantially preventingpuncturing of the catheter body 110 with a fractured element.

Optionally, where the flexible element distal portion 201 fracturesadjacent to the marker band 212 the skirt 220 substantially immobilizesthe distal portion 201 and prevents it from puncturing the catheter body110. In still another option, a skirt including several features (e.g.,knurling, corrugations, flaring or the like) is coupled with theflexible element distal portion 201 to enhance distribution of pushingand pulling forces and further reduce fracturing of the distal portion201. Additionally, the skirt with multiple features enhancesimmobilization of a fractured flexible element 200 to further preventpuncturing of the catheter body 110.

Referring now to FIG. 3, in another option, the skirt 220 is used with aflexible element distal portion 201 that is not coupled with the markerband 212. The pushing and pulling forces provided by the flexibleelement 200 are transmitted to the deflectable distal end portion 102through the skirt 220 anchored within the encapsulant 214. The pushingand pulling forces transmitted through the skirt 220 operate to deflectthe distal end portion 102 into desired orientations, for example, theorientations shown in FIGS. 1A, C. Because the skirt is coupled to theflexible element 200 without welding the element 200 experiences nostresses at an annealed region and the risk of fracturing the flexibleelement 200 is substantially reduced. As described above, the skirt 220and the flexible element 200 have tension and compression strengths atleast as great as the tension and compression strengths of theencapsulant 214 and thereby substantially reduce fracture of theflexible element 200. Optionally, the catheter body 110 (FIGS. 1A-C and2) is adapted to fail before failure of the flexible element 200 and theskirt 220, and thereby substantially prevent the puncturing of thecatheter body 110 by a fractured element.

Optionally, skirts 400A-D, 500A, B, 600, 700, 800A-D, 900 and 1000 areused in a similar manner to skirt 220 during operation of the catheterassembly 100. In another option, multiple skirts are used along theflexible element distal portion 201. In still another option, a skirtincluding several features (e.g., knurling, corrugations, flaring or thelike) is coupled with the flexible element distal portion 201 to enhanceanchoring of the distal portion 201 within the encapsulant 214.

FIG. 12 is a block diagram illustrating one example of a method 1200 formaking a catheter body. At 1202 a flexible element is positioned along acatheter liner. A distal portion of the flexible element extends alongat least a portion of a deflectable distal end portion of the catheterliner. At 1204 at least one skirt is coupled to the flexible elementdistal portion, and the at least one skirt extends at least part wayaround the flexible element distal portion. In one option, the flexibleelement distal portion proximal to the at least one skirt is free ofannealing (e.g., annealing caused by welds). At 1206 an encapsulant(e.g., PEBAX) is positioned around at least the flexible element distalportion and the deflectable distal end portion. At 1208, the encapsulantis squeezed around the flexible element distal portion and the skirt.The encapsulant forms at least a portion of a sidewall of thedeflectable distal end portion and at least the skirt is within thesidewall. The encapsulant is adapted to transmit pushing and pullingforces from the at least one skirt to the deflectable distal endportion. Additionally, the tension strength and compression strength ofthe flexible element and the at least one skirt are at least as strongas the encapsulant tension strength and compression strength. In anotheroption, the encapsulant is adapted to fail before the flexible elementand the at least one skirt.

Several options for the method 1200 follow. In one option, the method1200 includes substantially preventing a puncture of the encapsulant bythe flexible element, for instance, by anchoring the skirt within theencapsulant. In another option, a marker band is included in thedeflectable distal end portion. The skirt and the flexible elementdistal portion are positioned proximal to the marker band. The flexibleelement distal portion and the skirt are spaced proximally from themarker band, optionally, because the flexible element is not coupled tothe marker band. Features, such as flushing ports, are formed in thespace between the skirt and the marker band, in yet another option. Themarker band is coupled to the flexible element distal portion with aweld substantially adjacent to the deflectable distal end portion, inyet another option. Pushing and pulling forces a distributed between theskirt and the marker band to minimizes the forces experienced at theweld. The method 1200 includes, optionally, substantially preventingfracture of the flexible element adjacent to the marker band (e.g., atan annealed or weakened region).

In one option, the method 1200 includes flaring (e.g., by stamping) atleast one of the flexible element distal portion and the at least oneskirt. In another option, the skirt includes a clamp, and the method1200 includes deforming the skirt and the skirt grasps the flexibleelement distal portion. Deforming the skirt includes, optionally,crimping the clamp at a plurality of points along the clamp. In yetanother option, the method 1200 includes engaging a projection extendingfrom at least one of the skirt and the flexible element distal portionagainst the other of the skirt and the distal portion. Engaging theprojection includes seating the projection within at least one recesssized and shaped to receive the projection, in still yet another option.The recess is formed in at least one of the skirt and the flexibleelement distal portion. In a further option, engaging the projectionincludes using the projection to deform at least one of the flexibleelement and the skirt. For instance, the projection grasps the flexibleelement by deforming at least a portion of flexible element. Optionally,the method 1200 includes forming at least one recess (e.g., holes,corrugations, or the like) in the skirt. The at least one recess, inanother option, receives the encapsulant and thereby securely anchorsthe skirt and the flexible element distal portion in the encapsulant.The skirt and the flexible element distal portion are integral and therecesses are formed in the flexible element distal portion, in yetanother option.

The above described catheter allows for deflection of a deflectabledistal end portion while substantially preventing fracture of a flexibleelement. Pushing and pulling forces from the flexible element aretransmitted through the skirt to the encapsulant and the catheter linerat the deflectable distal end portion of the catheter. The skirtanchored in the encapsulant facilitates deflection of the deflectabledistal end portion through transmission of the pushing and pullingforces. In one option, the skirt is integral to the flexible elementdistal portion. Where the flexible element distal portion is not coupledto a marker band optionally, the skirt and the flexible element aredisposed along the catheter body proximal to a marker band used to seethe tip of the catheter body during procedures (e.g., with fluoroscopy).Proximally positioning the skirt provides additional space to includefeatures, for instance flush openings and the like, positioned betweenthe skirt and marker band.

The flexible element and the skirt have tension and compressionstrengths at least as great as the tension and compression strengths ofthe encapsulant to substantially reduce fracture of the flexibleelement. Optionally, the catheter body is adapted to fail before failureof the flexible element and the skirt, and puncturing of the catheterbody is thereby substantially prevented by a fractured element. Inanother option, the skirt is coupled to the flexible element distalportion without a weld. Fracturing of the flexible element is therebysubstantially reduced because stress is not applied to a weakenedannealed region. Additionally, the skirt is localized around theflexible element without extending remotely around the deflectabledistal end portion. The skirt thus provides improved strength anddurability against failure through shearing. Moreover, because the skirtis localized substantially adjacent to the flexible element pushing andpulling forces are not distributed around the catheter body. Thedeflectable distal end portion thus experiences an improved deflectionresponse with the concentrated pushing and pulling of the flexibleelement.

In another option, the skirt cooperates with the marker band coupled tothe flexible element distal portion. The marker band is coupled to theflexible element distally relative to the skirt. The skirt acts as asupplementary anchor and distributes pushing and pulling forces betweenthe marker band and itself. Fracturing of the flexible element adjacentto the marker band (e.g., the annealed region near a weld) issubstantially reduced because the pushing and pulling forces aredistributed between the skirt and the marker band. Additionally, wherethe flexible element distal portion does fracture adjacent the markerband, the skirt embedded in the encapsulant acts to substantiallyimmobilize the fractured flexible element and substantially preventpuncturing of the catheter body. Moreover, the skirt facilitatescontinued use of the catheter with a fractured flexible element becausethe skirt continues to function as an anchor and transmits pushing andpulling forces to the deflectable distal end portion.

Additionally, the encapsulant is squeezed around the catheter liner toeasily form an outer surface and sidewall of the catheter body and graspthe skirt. In one option, the skirt is in the sidewall and therebyprovides a larger moment to the deflectable distal end portion becauseit is positioned remotely from the center of the catheter body. Asdescribed above, the encapsulant flows around the skirt and, whenhardened, transmits tension and compression forces to the deflectabledistal end portion while also acting as the outer surface of thecatheter body. Complex manufacturing procedures including drillingand/or forming a pocket for an anchor and injecting an adhesive over theanchor are thereby avoided. Further, the skirt is retained along thecatheter body and the distal end therefore does not house the skirtand/or the flexible element in a hard tip. In one option, the distal endof the catheter body thereby has a soft atraumatic tip.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. It should be noted that embodiments discussed indifferent portions of the description or referred to in differentdrawings can be combined to form additional embodiments of the presentapplication. The scope of the invention should, therefore, be determinedwith reference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. A catheter, which comprises: a) a flexibleelement extending along a catheter liner with a distal portion having aflexible element distal end thereof extending along at least adeflectable distal end portion of the catheter liner; b) at least oneanchor contacted to the flexible element distal portion spacedproximally from the flexible element distal end; and c) an encapsulantcontacting at least the deflectable distal end portion of the catheterliner and the flexible element distal portion including the anchor. 2.The catheter of claim 1 wherein a band contacted to the catheter linerextends at least part way around a perimeter thereof with the flexibleelement residing radially between the catheter liner and the band. 3.The catheter of claim 2 wherein the band is spaced distally from the atleast one anchor.
 4. The catheter of claim 1 wherein the encapsulantforms at least a portion of a sidewall of the deflectable distal endportion of the catheter liner and at least the anchor is within thesidewall.
 5. The catheter of claim 1 wherein a braided sheath isdisposed around the catheter liner, the flexible element and the anchor.6. The catheter of claim 1 wherein an engaging portion of the anchor isdeformed to the flexible element distal portion.
 7. The catheter ofclaim 1 wherein the anchor is crimped to the flexible element distalportion at a plurality of locations.
 8. The catheter of claim 1 whereinthe anchor comprises at least one flared projection tapering toward anengaged portion the anchor contacting the flexible element.
 9. Thecatheter of claim 8 wherein the flared projection is filled with theencapsulant.
 10. A catheter, which comprises: a) a flexible elementpositioned along a catheter liner with a distal portion having aflexible element distal end thereof extending along at least adeflectable distal end portion of the catheter liner, wherein theflexible element extends from the deflectable distal end portion towarda proximal end portion of the catheter; b) an anchor comprising at leastone flared projection at at least one of an anchor proximal end and ananchor distal end, wherein an engaging portion of the anchor iscontacted to a flexible element distal portion, the flexible elementdistal portion being at least partially received within the flaredprojection of the anchor; c) a band contacted to the catheter liner, theband extending at least part way around a perimeter thereof with theflexible element residing radially between the catheter liner and theband; and d) an encapsulant contacting the flexible element distalportion and the anchor including its flared projection to thereby format least a portion of a sidewall of the catheter at a deflectable distalend portion thereof.
 11. The catheter of claim 10 wherein the catheterliner includes a delivery lumen.
 12. The catheter of claim 10 whereinthe encapsulant is provided through a braided sheath positioned aroundat least the anchor connected to the flexible element distal portion.13. The catheter of claim. 10 wherein the flared projection of theanchor tapers toward the anchor engaging portion.
 14. The catheter ofclaim 10 wherein the flared projection of the anchor extends annularlyaway from the flexible element, and includes a conical geometry.
 15. Thecatheter of claim 10 wherein the engaging portion of the anchor isclamped at least part way around the flexible element distal portion.